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Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-3907

MEDIUM · 6.4 CVSS v3.1 Published 2026-07-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
Remotely reachable Zero-click 6 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The Hostel plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'wphostel-book' shortcode in all versions up to and including 1.1.7. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, the second shortcode attribute (used as button text) is passed to the `$text` variable without sanitization at line 79 and then output directly into an HTML `value` attribute at line 91 without `esc_attr()` or any other escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The Hostel WordPress plugin is vulnerable to stored XSS via the 'wphostel-book' shortcode. The second shortcode attribute (used as button text) is stored in the $text variable without sanitization at line 79 and output directly into an HTML value attribute at line 91 without esc_attr() or any escaping, allowing authenticated attackers with Contributor-level access to inject arbitrary JavaScript.

MitigationAdd esc_attr() escaping to the $text variable output at line 91, or update to a patched version when released. Restrict shortcode usage permissions until patch is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if Hostel plugin is installed
    In WordPress admin, go to Plugins > Installed Plugins and look for 'Hostel' or check the wp-content/plugins directory for a folder named 'hostel' or similar. Alternatively, check your site for any pages using the wphostel-book shortcode.
    Affected if The Hostel WordPress plugin is present on the site
  2. Determine the installed plugin version
    In WordPress admin > Plugins, find the Hostel plugin and check the version number displayed. Compare it against any known version ranges or note that no fixed version is yet available.
    Affected if The plugin version is at or below the vulnerable version (no patched version released at time of CVE)
  3. Check for use of the vulnerable wphostel-book shortcode
    Search your WordPress posts, pages, and custom post types for the [wphostel-book] shortcode. Use wp-admin > Posts > Quick Edit > View to inspect raw content, or query the wp_posts table for the shortcode string.
    Affected if The wphostel-book shortcode is present in any published content
  4. Inspect the plugin source code for the vulnerability
    Locate the plugin file containing the shortcode handler (typically in the main plugin file or a shortcodes.php file). At line 79, check if the second shortcode attribute is assigned to $text without sanitization. At line 91, verify the $text variable is output in an HTML value attribute without esc_attr() wrapping.
    Affected if Line 79 stores the attribute to $text without sanitize_text_field() AND line 91 outputs $text without esc_attr() escaping
  5. Verify Contributor-level user accounts exist
    In WordPress admin, go to Users and review the role assigned to each account. Check if any users have the Contributor role.
    Affected if At least one user account with Contributor-level permissions exists on the site

Your environment is affected if the Hostel plugin is installed, uses the wphostel-book shortcode, and contains users with Contributor-level access, with unescaped $text output visible in the plugin source code at line 91.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Add esc_attr() escaping to the $text variable output at line 91, or update to a patched version when released. Restrict shortcode usage permissions until patch is applied.

Have this fixed Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-3907 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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